Ch 36: Reproduction and Development

Question 1

Sexual reproduction would be less successful (have lower reproductive success) than asexual reproduction when….

Answer 1

….a population is in a stable and favorable environment.

Question 2

Remember reproductive isolation mechanisms from the section on speciation? Which mechanism to maintain reproductive isolation would be least likely to occur in species with external fertilization.

a. gametic isolation
b. behavioral isolation
c. habitat isolation
d. hybrid sterility
e. mechanical isolation

Answer 2

e. mechanical isolation

Question 3

Which of the following would be evidence that asexually reproducing whiptail lizards evolved from sexually reproducing ancestors?

a. ) that they have to engage in courtship behaviors, including male-like behaviors, for the female to ovulate.
b. ) during development, they temporarily have testes that regress prior to sexual maturity.
c. ) all of the offspring are haploid.
d. ) they depend on favorable weather conditions for ovulation to occur.

Answer 3

a.) that they have to engage in courtship behaviors, including male-like behaviors, for the female to ovulate.

Question 4

What is the “cost” of sexual reproduction compared to asexual reproduction?

Answer 4

Females that reproduce sexually make half as many females as do females that reproduce asexually.

Question 5

Which of the following is the correct sequence of developmental events?

blastula --> gastrula --> cleavage
blastula --> cleavage --> gastrula
cleavage --> gastrula --> blastula
cleavage --> blastula --> gastrula
gastrula --> blastula --> cleavage

Answer 5

cleavage –> blastula –> gastrula

Question 6

If an embryo was exposed to an environmental toxin that blocked gastrulation, what would likely happen?

Answer 6

The embryo would not develop embryonic germ layers.